State emergency operations controller, Acting Deputy Commissioner Mark Murdoch, warned people not to leave their children or pets in cars, even for a short time.

"It doesn't take long for the temperature inside the car to soar, and for the effects of the heat to take hold," Mr Murdoch said in a statement.

"You might think it is inconvenient to take your child or pet with you, even if it is to go and pay for petrol or pop into a shop, but alternative could be worse.

"And for those who will flock to beaches, the rivers or pools to try to escape the heat and cool down, beware of the dangers of drinking alcohol and being out in the sun all day – it's not a good mix."